1 files changed, 235 insertions, 0 deletions
diff --git a/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/handler/ParticipantHandler.java b/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/handler/ParticipantHandler.java
new file mode 100644
index 000000000..980ab6ec1
--- /dev/null
+++ b/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/handler/ParticipantHandler.java
@@ -0,0 +1,235 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2021 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.clamp.controlloop.participant.intermediary.handler;
+
+import java.io.Closeable;
+import java.util.Objects;
+import lombok.Getter;
+import lombok.Setter;
+import org.onap.policy.clamp.controlloop.models.controlloop.concepts.Participant;
+import org.onap.policy.clamp.controlloop.models.controlloop.concepts.ParticipantHealthStatus;
+import org.onap.policy.clamp.controlloop.models.controlloop.concepts.ParticipantState;
+import org.onap.policy.clamp.controlloop.models.controlloop.concepts.ParticipantStatistics;
+import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantHealthCheck;
+import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantMessage;
+import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantResponseDetails;
+import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantResponseStatus;
+import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantStateChange;
+import org.onap.policy.clamp.controlloop.participant.intermediary.comm.MessageSender;
+import org.onap.policy.clamp.controlloop.participant.intermediary.comm.ParticipantStatusPublisher;
+import org.onap.policy.clamp.controlloop.participant.intermediary.parameters.ParticipantIntermediaryParameters;
+import org.onap.policy.models.tosca.authorative.concepts.ToscaConceptIdentifier;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * This class is responsible for managing the state of a participant.
+ */
+@Getter
+public class ParticipantHandler implements Closeable {
+    private static final Logger LOGGER = LoggerFactory.getLogger(ParticipantHandler.class);
+
+    private final ToscaConceptIdentifier participantType;
+    private final ToscaConceptIdentifier participantId;
+    private final MessageSender sender;
+    private final ControlLoopHandler controlLoopHandler;
+    private final ParticipantStatistics participantStatistics;
+
+    @Setter
+    private ParticipantState state = ParticipantState.UNKNOWN;
+
+    @Setter
+    private ParticipantHealthStatus healthStatus = ParticipantHealthStatus.UNKNOWN;
+
+    /**
+     * Constructor, set the participant ID and sender.
+     *
+     * @param parameters the parameters of the participant
+     * @param publisher the publisher for sending responses to messages
+     */
+    public ParticipantHandler(ParticipantIntermediaryParameters parameters, ParticipantStatusPublisher publisher) {
+        this.participantType = parameters.getParticipantType();
+        this.participantId = parameters.getParticipantId();
+        this.sender = new MessageSender(this, publisher, parameters.getReportingTimeInterval());
+        this.controlLoopHandler = new ControlLoopHandler(parameters, sender);
+        this.participantStatistics = new ParticipantStatistics();
+    }
+
+    @Override
+    public void close() {
+        sender.close();
+        controlLoopHandler.close();
+    }
+
+    /**
+     * Method which handles a participant state change event from clamp.
+     *
+     * @param stateChangeMsg participant state change message
+     */
+    public void handleParticipantStateChange(final ParticipantStateChange stateChangeMsg) {
+
+        if (!stateChangeMsg.appliesTo(participantType, participantId)) {
+            return;
+        }
+
+        ParticipantResponseDetails response = new ParticipantResponseDetails(stateChangeMsg);
+
+        switch (stateChangeMsg.getState()) {
+            case PASSIVE:
+                handlePassiveState(response);
+                break;
+            case ACTIVE:
+                handleActiveState(response);
+                break;
+            case SAFE:
+                handleSafeState(response);
+                break;
+            case TEST:
+                handleTestState(response);
+                break;
+            case TERMINATED:
+                handleTerminatedState(response);
+                break;
+            default:
+                LOGGER.debug("StateChange message has no state, state is null {}", stateChangeMsg.getParticipantId());
+                response.setResponseStatus(ParticipantResponseStatus.FAIL);
+                response.setResponseMessage("StateChange message has invalid state for participantId "
+                    + stateChangeMsg.getParticipantId());
+                break;
+        }
+
+        sender.sendResponse(response);
+    }
+
+
+    /**
+     * Method which handles a participant health check event from clamp.
+     *
+     * @param healthCheckMsg participant health check message
+     */
+    public void handleParticipantHealthCheck(final ParticipantHealthCheck healthCheckMsg) {
+        ParticipantResponseDetails response = new ParticipantResponseDetails(healthCheckMsg);
+        response.setResponseStatus(ParticipantResponseStatus.SUCCESS);
+        response.setResponseMessage(healthStatus.toString());
+
+        sender.sendResponse(response);
+    }
+
+    /**
+     * Method to handle when the new state from participant is active.
+     *
+     * @param response participant response
+     */
+    private void handleActiveState(final ParticipantResponseDetails response) {
+        handleStateChange(ParticipantState.ACTIVE, response);
+    }
+
+    /**
+     * Method to handle when the new state from participant is passive.
+     *
+     * @param response participant response
+     */
+    private void handlePassiveState(final ParticipantResponseDetails response) {
+        handleStateChange(ParticipantState.PASSIVE, response);
+    }
+
+    /**
+     * Method to handle when the new state from participant is safe.
+     *
+     * @param response participant response
+     */
+    private void handleSafeState(final ParticipantResponseDetails response) {
+        handleStateChange(ParticipantState.SAFE, response);
+    }
+
+    /**
+     * Method to handle when the new state from participant is TEST.
+     *
+     * @param response participant response
+     */
+    private void handleTestState(final ParticipantResponseDetails response) {
+        handleStateChange(ParticipantState.TEST, response);
+    }
+
+    /**
+     * Method to handle when the new state from participant is Terminated.
+     *
+     * @param response participant response
+     */
+    private void handleTerminatedState(final ParticipantResponseDetails response) {
+        handleStateChange(ParticipantState.TERMINATED, response);
+    }
+
+    private void handleStateChange(ParticipantState newParticipantState, ParticipantResponseDetails response) {
+        if (state.equals(newParticipantState)) {
+            response.setResponseStatus(ParticipantResponseStatus.SUCCESS);
+            response.setResponseMessage("Participant already in state " + newParticipantState);
+        } else {
+            response.setResponseStatus(ParticipantResponseStatus.SUCCESS);
+            response.setResponseMessage("Participant state changed from " + state + " to " + newParticipantState);
+            state = newParticipantState;
+        }
+    }
+
+    /**
+     * Method to update participant state.
+     *
+     * @param definition participant definition
+     * @param participantState participant state
+     */
+    public Participant updateParticipantState(ToscaConceptIdentifier definition,
+            ParticipantState participantState) {
+        if (!Objects.equals(definition, participantId)) {
+            LOGGER.debug("No participant with this ID {}", definition.getName());
+            return null;
+        }
+        ParticipantResponseDetails response = new ParticipantResponseDetails();
+        handleStateChange(participantState, response);
+        sender.sendResponse(response);
+        return getParticipant(definition.getName(), definition.getVersion());
+    }
+
+    /**
+     * Get participants as a {@link Participant} class.
+     *
+     * @return the participant
+     */
+    public Participant getParticipant(String name, String version) {
+        if (participantId.getName().equals(name)) {
+            Participant participant = new Participant();
+            participant.setDefinition(participantId);
+            participant.setParticipantState(state);
+            participant.setHealthStatus(healthStatus);
+            return participant;
+        }
+        return null;
+    }
+
+    /**
+     * Check if a participant message applies to this participant handler.
+     *
+     * @param partipantMsg the message to check
+     * @return true if it applies, false otherwise
+     */
+    public boolean canHandle(ParticipantMessage partipantMsg) {
+        return partipantMsg.appliesTo(participantType, participantId);
+    }
+}